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<a name="boost.compute.max_element"></a><div class="titlepage"></div>
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<h2><span class="refentrytitle">Function max_element</span></h2>
<p>boost::compute::max_element</p>
</div>
<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../../boost_compute/reference.html#header.boost.compute.algorithm.max_element_hpp" title="Header &lt;boost/compute/algorithm/max_element.hpp&gt;">boost/compute/algorithm/max_element.hpp</a>&gt;

</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> InputIterator<span class="special">,</span> <span class="keyword">typename</span> Compare<span class="special">&gt;</span> 
  <span class="identifier">InputIterator</span> 
  <span class="identifier">max_element</span><span class="special">(</span><span class="identifier">InputIterator</span> first<span class="special">,</span> <span class="identifier">InputIterator</span> last<span class="special">,</span> <span class="identifier">Compare</span> compare<span class="special">,</span> 
              <span class="identifier">command_queue</span> <span class="special">&amp;</span> queue <span class="special">=</span> <span class="identifier">system</span><span class="special">::</span><span class="identifier">default_queue</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> InputIterator<span class="special">&gt;</span> 
  <span class="identifier">InputIterator</span> 
  <span class="identifier">max_element</span><span class="special">(</span><span class="identifier">InputIterator</span> first<span class="special">,</span> <span class="identifier">InputIterator</span> last<span class="special">,</span> 
              <span class="identifier">command_queue</span> <span class="special">&amp;</span> queue <span class="special">=</span> <span class="identifier">system</span><span class="special">::</span><span class="identifier">default_queue</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="idm46604986730160"></a><h2>Description</h2>
<p>Returns an iterator pointing to the element in the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) with the maximum value.</p>
<p>
For example, to find <code class="computeroutput">int2</code> value with maximum first component in given vector: </p>
<pre class="programlisting"><span class="comment">// comparison function object</span>
<span class="identifier">BOOST_COMPUTE_FUNCTION</span><span class="special">(</span><span class="keyword">bool</span><span class="special">,</span> <span class="identifier">compare_first</span><span class="special">,</span> <span class="special">(</span><span class="keyword">const</span> <span class="identifier">int2_</span> <span class="special">&amp;</span><span class="identifier">a</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">int2_</span> <span class="special">&amp;</span><span class="identifier">b</span><span class="special">)</span><span class="special">,</span>
<span class="special">{</span>
    <span class="keyword">return</span> <span class="identifier">a</span><span class="special">.</span><span class="identifier">x</span> <span class="special">&lt;</span> <span class="identifier">b</span><span class="special">.</span><span class="identifier">x</span><span class="special">;</span>
<span class="special">}</span><span class="special">)</span><span class="special">;</span>

<span class="comment">// create vector</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">uint2_</span><span class="special">&gt;</span> <span class="identifier">data</span> <span class="special">=</span> <span class="special">...</span>

<span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">uint2_</span><span class="special">&gt;</span><span class="special">::</span><span class="identifier">iterator</span> <span class="identifier">max</span> <span class="special">=</span>
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">compute</span><span class="special">::</span><span class="identifier">max_element</span><span class="special">(</span><span class="identifier">data</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">data</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">compare_first</span><span class="special">,</span> <span class="identifier">queue</span><span class="special">)</span><span class="special">;</span>
</pre>
<p>Space complexity on CPUs: \Omega(1)<br>
 Space complexity on GPUs: \Omega(N)</p>
<p><span class="bold"><strong>See Also:</strong></span></p>
<p>min_element() </p>
<p>
</p>
<p>
</p>
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<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
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<td><p><span class="term"><code class="computeroutput">compare</code></span></p></td>
<td><p>comparison function object which returns true if the first argument is less than (i.e. is ordered before) the second. </p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">first</code></span></p></td>
<td><p>first element in the input range </p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">last</code></span></p></td>
<td><p>last element in the input range </p></td>
</tr>
<tr>
<td><p><span class="term"><code class="computeroutput">queue</code></span></p></td>
<td><p>command queue to perform the operation</p></td>
</tr>
</tbody>
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<td align="right"><div class="copyright-footer">Copyright © 2013, 2014 Kyle Lutz<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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